Diagnosis of pyogenic pelvic inflammatory diseases by Tc-99m-HMPAO leucocyte scintigraphy

Pelvic inflammatory disease (PID) is one of the major health problems of wo men of child-bearing age. Among the most serious complications of PID is th e formation of a tube-ovarian abscess (TOA). Early diagnosis of this condit ion may prevent serious surgical complications such as peritonitis and seps is, which may be fatal. The purpose of this study was to investigate the ef ficacy of technetium-99m hexamethylpropylene amine oxime (HMPAO) leucocyte scintigraphy in the diagnosis of TOA. Twenty women with high clinical suspi cion of TOA underwent Tc-99m-HMPAO leucocyte scintigraphy. The labelling of leucocytes with (99)mTc-HMPAO was performed according to a standard protoc ol. Scans were obtained at 1, 3 and 24 h following the injection of the lab elled leucocytes. In eight cases the early and/or late scan was positive, i n Il cases it was negative, and in one case of ovarian cyst torsion, confir med by laparoscopy, it showed slight uptake in the capsule of the cyst (fal se-positive). The sensitivity of (99)mTc-HMPAO leucocyte scintigraphy was 1 00%, specificity 91.6%, positive predictive value 89%, negative predictive value 100% and overall accuracy 95%. It is concluded that leucocyte scintig raphy is a non-invasive, safe, physiological and accurate procedure for the diagnosis of TOA. The 24-h scan is crucial, since in some cases the absces s was not clearly visualized on the early scan. Leucocyte scintigraphy may reduce the need for CT, diagnostic laparoscopy and unnecessary invasive sur gical procedures.